“Besides, one former member of the team from [Charles’] Prince of Wales days reveals that the king had actually undergone a cancer scare some years before,” Hardman wrote in a passage of the book, excerpted by the Mail on Sunday.

King Charlesannounced he was diagnosed with cancer earlier this year, but an insider claimed the monarch had a previous brush with it before ascending to the throne. "Cancer is a very scary word if you're a king or anyone else.